1. Technical Field
The present invention relates to an interactive projector capable of receiving an instruction of the user to a projected screen with a pointing element, and a method of controlling the projector.
2. Related Art
JP-A-2012-150636 and JP-T-2008-520034 disclose a projection display device (projector) capable of projecting a projected screen on a screen, and at the same time taking an image, which includes an object such as a finger or a light emitting pen, with a camera to detect the position of the object using the taken image. An object such as a finger is used as a pointing element for making an instruction to the projection image. In other words, when the tip of the object has contact with the screen, the projector recognizes that a predetermined instruction such as drawing is input with respect to the projected screen, and then redraws the projected screen in accordance with the instruction. Therefore, it is possible for the user to input a variety of instructions using the projected screen as a user interface. The projector of the type capable of using the projected screen on the screen as an inputting user interface as described above is referred to as an “interactive projector.” Further, the object used for making an instruction to the projected screen is referred to as a “pointing element.”
In the typical interactive projector, whether or not an instruction is made using the pointing element is determined in accordance with whether or not the tip of the pointing element has contact with the screen. The contact of the pointing element can be detected based on the distance between the tip of the pointing element and the screen. However, there has been a problem that the projector, which detects the three-dimensional position of the tip of the pointing element using a plurality of cameras in order to calculate the distance between the tip of the pointing element and the screen, takes time to calculate the three-dimensional position, or fails to obtain sufficient detection accuracy. Therefore, there has been demanded a technology of performing the detection process on whether or not the pointing element has contact with the screen in a nontraditional way.